Currently, JetBlue has an affiliate link on their website which allows you to earn 3 JetBlue “True Blue” points per dollar spent at Amazon.com. However, starting on March 27, 2018, you will no longer earn any JetBlue points for purchases made at Amazon.com, while shopping on the ground. You will still earn 3 JetBlue points per dollar spent at Amazon.com made during in-flight purchases (while flying JetBlue), but you will no longer earn the bonus points while shopping on the ground.
Here’s the official notice by JetBlue.
And don’t forget to use Amazon gift cards to double/triple dip on your points. Good luck!